ShapePreservingLength(Geometry,LinearUnit) Method

In This Topic

Calculates the length of the geometry on the surface of the Earth ellipsoid. This method preserves the shape of the geometry in its coordinate system.

Syntax

Visual Basic (Declaration)
C#

Overloads Function ShapePreservingLength( _
   ByVal geometry As Geometry, _
   ByVal lengthUnit As LinearUnit _
) As Double

double ShapePreservingLength( 
   Geometry geometry,
   LinearUnit lengthUnit
)

Parameters

geometry: The input geometry. Cannot be null and its spatial reference cannot be null.
lengthUnit: The unit of the output length. If null, then the length is in meters.

Return Value

Shape preserving length of the geometry in . If is null, then the shape preserving length is in meters.

If the geometry is empty, then zero is returned.

Exceptions

Exception	Description
System.ArgumentNullException	Geometry is null or geometry's spatial reference is null.
System.NotImplementedException	The method is not implemented for GeometryBag or Multipatch.
ArcGIS.Core.Geometry.Exceptions.ProjectionEngineException	Geometry is missing a spatial reference.
System.NotImplementedException	Spatial reference of geometryis an image coordinate system.

Remarks

This method preserves the shape of the geometry in its coordinate system. In other words, the length will be calculated for the geometry you see in the map. For example, if you have a polyline with only two vertices that represents the equator, the length returned will be the length of the equator.

Example

Calculate length of geometry on surface of Earth's ellipsoid - ShapePreservingLength

{
  // pt
  MapPoint pt = MapPointBuilderEx.CreateMapPoint(1.0, 3.0, SpatialReferences.WebMercator);
  double len = GeometryEngine.Instance.ShapePreservingLength(pt);          // len = 0

  List<MapPoint> pts =
  [
    MapPointBuilderEx.CreateMapPoint(1.0, 1.0, 3.0),
  MapPointBuilderEx.CreateMapPoint(1.0, 3.0, 3.0),
  MapPointBuilderEx.CreateMapPoint(3, 3, 3.0),
  MapPointBuilderEx.CreateMapPoint(3.0, 1.0, 3.0),
];

  // multipoint
  Multipoint mPt = MultipointBuilderEx.CreateMultipoint(pts);
  len = GeometryEngine.Instance.ShapePreservingLength(mPt);                // len = 0

  // polyline
  polyline = PolylineBuilderEx.CreatePolyline(pts, SpatialReferences.WGS84);
  len = GeometryEngine.Instance.ShapePreservingLength(polyline);

  // polygon
  polygon = PolygonBuilderEx.CreatePolygon(pts, SpatialReferences.WGS84);
  len = GeometryEngine.Instance.ShapePreservingLength(polygon);

  polyline = PolylineBuilderEx.CreatePolyline(
  [
    MapPointBuilderEx.CreateMapPoint( -170, 0),
  MapPointBuilderEx.CreateMapPoint( 170, 0)
  ], SpatialReferences.WGS84);


  var length_meters = GeometryEngine.Instance.ShapePreservingLength(polyline); // , LinearUnits.Meters);
  var length_miles = GeometryEngine.Instance.ShapePreservingLength(polyline, LinearUnit.Miles);

  // length_meters - 37848626.869713023
  // length_miles - 23518.046402579574
}

Requirements

Target Platforms: Windows 11 Home, Pro, Enterprise (64 bit)

ArcGIS Pro version: 3.0 or higher.

Reference

IGeometryEngine Interface
IGeometryEngine Members
Overload List

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